Fig. 4.

Myeloid differentiation factor 88 (MyD88)-deficient mice have enhanced organic dust extract (ODE)-mediated mucin (Muc)5ac expression. Wild-type (WT) and MyD88 knockout (KO) mice were treated with intranasal inhalation of saline or ODE for 1 wk, whereupon lung homogenates were collected. Bar graphs depict mean value and SE for Muc5ac (A) and Muc5b (B) mRNA expression, as measured by quantitative PCR (qPCR). Mucin expression was normalized to GAPDH and reported as fold change relative to mean WT saline condition (n = 12–14 mice per group from 6 separate experiments). C and D: secretoglobin 1a1 (Scgb1a1) and forkhead box j1 (Foxj1) expression in lung homogenates was measured by qPCR from naïve WT and MyD88-KO mice not challenged with either saline or ODE (n = 4 mice per group). E: representative images of naïve WT and MyD88-KO mouse airways with α-tubulin for cilia and Scgb1a1 immunostaining. Original scale bar, 50 μm. *P < 0.05, significant difference between ODE and saline. **P < 0.05, significant difference between WT and MyD88-KO mice. DAPI, 4′,6-diamidino-2-phenylindole.